Re: [HACKERS] Cmpact commits and changeset extraction

2013-10-14 Thread Robert Haas
On Fri, Oct 11, 2013 at 4:05 PM, Andres Freund wrote: >> Maybe. The original reason we added compact commits was because we >> thought that making unlogged tables logged and visca/versa was going >> to require adding still more stuff to the commit record. I'm no >> longer sure that's the case an

Re: [HACKERS] Cmpact commits and changeset extraction

2013-10-11 Thread Andres Freund
On 2013-10-01 10:12:13 -0400, Robert Haas wrote: > On Tue, Oct 1, 2013 at 7:26 AM, Andres Freund wrote: > > On 2013-10-01 06:20:20 -0400, Robert Haas wrote: > >> On Mon, Sep 30, 2013 at 5:34 PM, Andres Freund > >> wrote: > >> >> What's wrong with #1? > >> > > >> > It seems confusing that a chang

Re: [HACKERS] Cmpact commits and changeset extraction

2013-10-01 Thread Robert Haas
On Tue, Oct 1, 2013 at 7:26 AM, Andres Freund wrote: > On 2013-10-01 06:20:20 -0400, Robert Haas wrote: >> On Mon, Sep 30, 2013 at 5:34 PM, Andres Freund >> wrote: >> >> What's wrong with #1? >> > >> > It seems confusing that a changeset stream in database #1 will contain >> > commits (without c

Re: [HACKERS] Cmpact commits and changeset extraction

2013-10-01 Thread Andres Freund
On 2013-10-01 06:20:20 -0400, Robert Haas wrote: > On Mon, Sep 30, 2013 at 5:34 PM, Andres Freund wrote: > >> What's wrong with #1? > > > > It seems confusing that a changeset stream in database #1 will contain > > commits (without corresponding changes) from database #2. Seems like aaa > > pola v

Re: [HACKERS] Cmpact commits and changeset extraction

2013-10-01 Thread Robert Haas
On Mon, Sep 30, 2013 at 5:34 PM, Andres Freund wrote: >> What's wrong with #1? > > It seems confusing that a changeset stream in database #1 will contain > commits (without corresponding changes) from database #2. Seems like aaa > pola violation to me. I don't really see the problem. A transacti

Re: [HACKERS] Cmpact commits and changeset extraction

2013-09-30 Thread Andres Freund
On 2013-09-30 14:22:22 -0400, Robert Haas wrote: > On Mon, Sep 30, 2013 at 10:50 AM, Andres Freund > wrote: > > Changeset extraction only works in the context of a single database but > > has to scan through xlog records from multiple databases. Most records > > are easy to skip because they cont

Re: [HACKERS] Cmpact commits and changeset extraction

2013-09-30 Thread Robert Haas
On Mon, Sep 30, 2013 at 10:50 AM, Andres Freund wrote: > Changeset extraction only works in the context of a single database but > has to scan through xlog records from multiple databases. Most records > are easy to skip because they contain the database in the relfilenode or > are just not intere

[HACKERS] Cmpact commits and changeset extraction

2013-09-30 Thread Andres Freund
Hi, Changeset extraction only works in the context of a single database but has to scan through xlog records from multiple databases. Most records are easy to skip because they contain the database in the relfilenode or are just not interesting for logical replication. The only exception are compa